This is related to the way the iPhone displays the saved images. I don't think we can change this from Chrome.
If you send the image using gmail it will animate (i.e. the image is saved as a GIF, the iPhone does not want to animate it).
Do you think we should investigate this further?

I am currently investigating this with the same image saved three times.

IMG_0169 - M52
IMG_0170 - Safari
IMG_0171 - M54

I sent the images to myself in Gmail and none of them animate, but it seems it only
took the first frame of the GIF for each of the attachments.  (The MD5 of all of the
attachments is also the same). Perhaps it's a Gmail bug.

If I look at the files in Image Capture on the device, it seems Chrome is only saving
the first frame of the GIF while Safari saves all of the frames (see image size).
When the files are imported to the computer, the Safari image has a different MD5
than the other two, which are the same.

Deleted: Screen Shot 2016-08-08 at 7.31.07 AM.png 49.6 KB

	Screen Shot 2016-08-08 at 7.31.07 AM.png 49.6 KB View Download

This was originally reported from App Store reviews, and there are other recent
ones mentioning it.  

Deleted: Screen Shot 2016-08-11 at 10.59.20 AM.png 20.0 KB

	Screen Shot 2016-08-11 at 10.59.20 AM.png 20.0 KB View Download

This is a regression from M51. Probably due to the passage from ALAssetsLibrary to PHPhotoLibrary.

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/chrome/ios_internal.git/+/e199538e737ba56c396f5298ae11ad33a88d7d0c

commit e199538e737ba56c396f5298ae11ad33a88d7d0c
Author: gambard <gambard@google.com>
Date: Tue Aug 16 08:58:24 2016

Would it be possible to add a unit or integration test for this case so it won't regress in the future?

Gautier: Is this fixed now? Or do you have more to come?

 Issue 646149  has been merged into this issue.

This should be fixed now.
The bug is still open because I need to write the test case.

Opening bug to public and marking fixed. Please file a new bug for the test cases so this can be verified by Test.

Animated gif (https://media.giphy.com/media/iPTTjEt19igne/giphy.gif) when saved from chrome and attached in gmail the image is animated. 
Verified on iPhone 6s(9.3.5), iPad Air 2(10.0.2) in 54.0.2840.39

 Issue 652158  has been merged into this issue.

It seems that the bug is not fixed in testflight (bug in 54.0.2840.58 beta).

My bad, it is fixed but the name might not be right, I will fix this later.

I can confirm that at the very least the bug is not fixed in the latest stable release on iOS. It's also worth noting that this bug appears present in all third party browsers except for Opera. 

Yes, it is present in the current stable release but as it is fixed in the beta release, it should be fixed in the next version (54).
The next release is scheduled soon but in the meantime you can install the beta if needed: https://www.google.com/chrome/browser/beta.html
If it is still broken for you in 54, please reopen the bug.

gambard@, You mean 55 here instead of 54 right?

gambard: In #16 and #17, are you referring to  crbug.com/656641  instead?

Is there another change (other than the one in #7) needed to fix the GIF bug? Thanks.

jasonkliu: there is no other change needed, the change #7 fixes the GIF bug.  crbug.com/656641  is a minor issue about image naming.

cmasso: I might be wrong but yesterday I had 53 as stable release and 54 as beta release. The bug is fixed in 54, as #14 mentioned.

As it might not be clear enough:
There is no bug in the current beta (54), I was wrong on #16.
I was mistaken because I tried to attach the image in gmail using gmail->new message->add attachment->myImage.gif. This does not work even for gif downloaded from safari.
A way to have a working gif in a gmail message is: photos->myImage.gif->share with gmail.

I just updated to version 54.0.2840.66 on my iPhone 6, and I am still experiencing this issue. 

I opened a gif image in Chrome, I did a long press to select Save Image, and then I copied the gif into a text message and sent it. The text message only displays the first frame. 

I tried the same exact steps in iOS Safari, and the image displays as an animated GIF in the text message.

Hi,

I just tried this out and wasn't able to reproduce the bug.  I used this GIF: https://media.giphy.com/media/9fbYYzdf6BbQA/giphy.gif

When you "copied the gif into a text message", did you use the iOS Share Sheet?
Can you share the URL of the gif you were using?  

Thanks.

I found a (kind-of) repro case, but it's WAI.
I guess this is actually a video, not a GIF (the URL was misleading).

1. Go to http://imgur.com/r/gifs/8fn4mB3.
2. Long press on the image and download it. 

On desktop, it's a video:
    <video  preload="auto" autoplay="autoplay" muted="muted" loop="loop" webkit-playsinline></video>
    <div class="video-elements">
      <source src="//i.imgur.com/8fn4mB3.mp4" type="video/mp4">
    </div>

Change your User Agent to mobile and now it's a picture:
    <video poster="http://i.imgur.com/8fn4mB3l.jpg" loop="" class="gif-video" id="video-8fn4mB3" muted="muted" style="height: 404px">
      <source src="http://i.imgur.com/8fn4mB3.mp4" type="video/mp4">
    </video>

If you look at http://i.imgur.com/8fn4mB3l.jpg, it's a 640x359 image which is the same when downloaded in Safari or Chrome.

Ok, tried it again with a real GIF: http://m.imgur.com/a/JBHEC

Interestingly, Safari saves it as a png while Chrome saves it as a gif.  Both animate in iMessage.